1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * DDP: An implementation of the AppleTalk DDP protocol for
4 * Ethernet 'ELAP'.
5 *
6 * Alan Cox <alan@lxorguk.ukuu.org.uk>
7 *
8 * With more than a little assistance from
9 *
10 * Wesley Craig <netatalk@umich.edu>
11 *
12 * Fixes:
13 * Neil Horman : Added missing device ioctls
14 * Michael Callahan : Made routing work
15 * Wesley Craig : Fix probing to listen to a
16 * passed node id.
17 * Alan Cox : Added send/recvmsg support
18 * Alan Cox : Moved at. to protinfo in
19 * socket.
20 * Alan Cox : Added firewall hooks.
21 * Alan Cox : Supports new ARPHRD_LOOPBACK
22 * Christer Weinigel : Routing and /proc fixes.
23 * Bradford Johnson : LocalTalk.
24 * Tom Dyas : Module support.
25 * Alan Cox : Hooks for PPP (based on the
26 * LocalTalk hook).
27 * Alan Cox : Posix bits
28 * Alan Cox/Mike Freeman : Possible fix to NBP problems
29 * Bradford Johnson : IP-over-DDP (experimental)
30 * Jay Schulist : Moved IP-over-DDP to its own
31 * driver file. (ipddp.c & ipddp.h)
32 * Jay Schulist : Made work as module with
33 * AppleTalk drivers, cleaned it.
34 * Rob Newberry : Added proxy AARP and AARP
35 * procfs, moved probing to AARP
36 * module.
37 * Adrian Sun/
38 * Michael Zuelsdorff : fix for net.0 packets. don't
39 * allow illegal ether/tokentalk
40 * port assignment. we lose a
41 * valid localtalk port as a
42 * result.
43 * Arnaldo C. de Melo : Cleanup, in preparation for
44 * shared skb support 8)
45 * Arnaldo C. de Melo : Move proc stuff to atalk_proc.c,
46 * use seq_file
47 */
48
49 #include <linux/capability.h>
50 #include <linux/module.h>
51 #include <linux/if_arp.h>
52 #include <linux/termios.h> /* For TIOCOUTQ/INQ */
53 #include <linux/compat.h>
54 #include <linux/slab.h>
55 #include <net/datalink.h>
56 #include <net/psnap.h>
57 #include <net/sock.h>
58 #include <net/tcp_states.h>
59 #include <net/route.h>
60 #include <net/compat.h>
61 #include <linux/atalk.h>
62 #include <linux/highmem.h>
63
64 struct datalink_proto *ddp_dl, *aarp_dl;
65 static const struct proto_ops atalk_dgram_ops;
66
67 /**************************************************************************\
68 * *
69 * Handlers for the socket list. *
70 * *
71 \**************************************************************************/
72
73 HLIST_HEAD(atalk_sockets);
74 DEFINE_RWLOCK(atalk_sockets_lock);
75
__atalk_insert_socket(struct sock * sk)76 static inline void __atalk_insert_socket(struct sock *sk)
77 {
78 sk_add_node(sk, &atalk_sockets);
79 }
80
atalk_remove_socket(struct sock * sk)81 static inline void atalk_remove_socket(struct sock *sk)
82 {
83 write_lock_bh(&atalk_sockets_lock);
84 sk_del_node_init(sk);
85 write_unlock_bh(&atalk_sockets_lock);
86 }
87
atalk_search_socket(struct sockaddr_at * to,struct atalk_iface * atif)88 static struct sock *atalk_search_socket(struct sockaddr_at *to,
89 struct atalk_iface *atif)
90 {
91 struct sock *s;
92
93 read_lock_bh(&atalk_sockets_lock);
94 sk_for_each(s, &atalk_sockets) {
95 struct atalk_sock *at = at_sk(s);
96
97 if (to->sat_port != at->src_port)
98 continue;
99
100 if (to->sat_addr.s_net == ATADDR_ANYNET &&
101 to->sat_addr.s_node == ATADDR_BCAST)
102 goto found;
103
104 if (to->sat_addr.s_net == at->src_net &&
105 (to->sat_addr.s_node == at->src_node ||
106 to->sat_addr.s_node == ATADDR_BCAST ||
107 to->sat_addr.s_node == ATADDR_ANYNODE))
108 goto found;
109
110 /* XXXX.0 -- we got a request for this router. make sure
111 * that the node is appropriately set. */
112 if (to->sat_addr.s_node == ATADDR_ANYNODE &&
113 to->sat_addr.s_net != ATADDR_ANYNET &&
114 atif->address.s_node == at->src_node) {
115 to->sat_addr.s_node = atif->address.s_node;
116 goto found;
117 }
118 }
119 s = NULL;
120 found:
121 read_unlock_bh(&atalk_sockets_lock);
122 return s;
123 }
124
125 /**
126 * atalk_find_or_insert_socket - Try to find a socket matching ADDR
127 * @sk: socket to insert in the list if it is not there already
128 * @sat: address to search for
129 *
130 * Try to find a socket matching ADDR in the socket list, if found then return
131 * it. If not, insert SK into the socket list.
132 *
133 * This entire operation must execute atomically.
134 */
atalk_find_or_insert_socket(struct sock * sk,struct sockaddr_at * sat)135 static struct sock *atalk_find_or_insert_socket(struct sock *sk,
136 struct sockaddr_at *sat)
137 {
138 struct sock *s;
139 struct atalk_sock *at;
140
141 write_lock_bh(&atalk_sockets_lock);
142 sk_for_each(s, &atalk_sockets) {
143 at = at_sk(s);
144
145 if (at->src_net == sat->sat_addr.s_net &&
146 at->src_node == sat->sat_addr.s_node &&
147 at->src_port == sat->sat_port)
148 goto found;
149 }
150 s = NULL;
151 __atalk_insert_socket(sk); /* Wheee, it's free, assign and insert. */
152 found:
153 write_unlock_bh(&atalk_sockets_lock);
154 return s;
155 }
156
atalk_destroy_timer(struct timer_list * t)157 static void atalk_destroy_timer(struct timer_list *t)
158 {
159 struct sock *sk = from_timer(sk, t, sk_timer);
160
161 if (sk_has_allocations(sk)) {
162 sk->sk_timer.expires = jiffies + SOCK_DESTROY_TIME;
163 add_timer(&sk->sk_timer);
164 } else
165 sock_put(sk);
166 }
167
atalk_destroy_socket(struct sock * sk)168 static inline void atalk_destroy_socket(struct sock *sk)
169 {
170 atalk_remove_socket(sk);
171 skb_queue_purge(&sk->sk_receive_queue);
172
173 if (sk_has_allocations(sk)) {
174 timer_setup(&sk->sk_timer, atalk_destroy_timer, 0);
175 sk->sk_timer.expires = jiffies + SOCK_DESTROY_TIME;
176 add_timer(&sk->sk_timer);
177 } else
178 sock_put(sk);
179 }
180
181 /**************************************************************************\
182 * *
183 * Routing tables for the AppleTalk socket layer. *
184 * *
185 \**************************************************************************/
186
187 /* Anti-deadlock ordering is atalk_routes_lock --> iface_lock -DaveM */
188 struct atalk_route *atalk_routes;
189 DEFINE_RWLOCK(atalk_routes_lock);
190
191 struct atalk_iface *atalk_interfaces;
192 DEFINE_RWLOCK(atalk_interfaces_lock);
193
194 /* For probing devices or in a routerless network */
195 struct atalk_route atrtr_default;
196
197 /* AppleTalk interface control */
198 /*
199 * Drop a device. Doesn't drop any of its routes - that is the caller's
200 * problem. Called when we down the interface or delete the address.
201 */
atif_drop_device(struct net_device * dev)202 static void atif_drop_device(struct net_device *dev)
203 {
204 struct atalk_iface **iface = &atalk_interfaces;
205 struct atalk_iface *tmp;
206
207 write_lock_bh(&atalk_interfaces_lock);
208 while ((tmp = *iface) != NULL) {
209 if (tmp->dev == dev) {
210 *iface = tmp->next;
211 dev_put(dev);
212 kfree(tmp);
213 dev->atalk_ptr = NULL;
214 } else
215 iface = &tmp->next;
216 }
217 write_unlock_bh(&atalk_interfaces_lock);
218 }
219
atif_add_device(struct net_device * dev,struct atalk_addr * sa)220 static struct atalk_iface *atif_add_device(struct net_device *dev,
221 struct atalk_addr *sa)
222 {
223 struct atalk_iface *iface = kzalloc(sizeof(*iface), GFP_KERNEL);
224
225 if (!iface)
226 goto out;
227
228 dev_hold(dev);
229 iface->dev = dev;
230 dev->atalk_ptr = iface;
231 iface->address = *sa;
232 iface->status = 0;
233
234 write_lock_bh(&atalk_interfaces_lock);
235 iface->next = atalk_interfaces;
236 atalk_interfaces = iface;
237 write_unlock_bh(&atalk_interfaces_lock);
238 out:
239 return iface;
240 }
241
242 /* Perform phase 2 AARP probing on our tentative address */
atif_probe_device(struct atalk_iface * atif)243 static int atif_probe_device(struct atalk_iface *atif)
244 {
245 int netrange = ntohs(atif->nets.nr_lastnet) -
246 ntohs(atif->nets.nr_firstnet) + 1;
247 int probe_net = ntohs(atif->address.s_net);
248 int probe_node = atif->address.s_node;
249 int netct, nodect;
250
251 /* Offset the network we start probing with */
252 if (probe_net == ATADDR_ANYNET) {
253 probe_net = ntohs(atif->nets.nr_firstnet);
254 if (netrange)
255 probe_net += jiffies % netrange;
256 }
257 if (probe_node == ATADDR_ANYNODE)
258 probe_node = jiffies & 0xFF;
259
260 /* Scan the networks */
261 atif->status |= ATIF_PROBE;
262 for (netct = 0; netct <= netrange; netct++) {
263 /* Sweep the available nodes from a given start */
264 atif->address.s_net = htons(probe_net);
265 for (nodect = 0; nodect < 256; nodect++) {
266 atif->address.s_node = (nodect + probe_node) & 0xFF;
267 if (atif->address.s_node > 0 &&
268 atif->address.s_node < 254) {
269 /* Probe a proposed address */
270 aarp_probe_network(atif);
271
272 if (!(atif->status & ATIF_PROBE_FAIL)) {
273 atif->status &= ~ATIF_PROBE;
274 return 0;
275 }
276 }
277 atif->status &= ~ATIF_PROBE_FAIL;
278 }
279 probe_net++;
280 if (probe_net > ntohs(atif->nets.nr_lastnet))
281 probe_net = ntohs(atif->nets.nr_firstnet);
282 }
283 atif->status &= ~ATIF_PROBE;
284
285 return -EADDRINUSE; /* Network is full... */
286 }
287
288
289 /* Perform AARP probing for a proxy address */
atif_proxy_probe_device(struct atalk_iface * atif,struct atalk_addr * proxy_addr)290 static int atif_proxy_probe_device(struct atalk_iface *atif,
291 struct atalk_addr *proxy_addr)
292 {
293 int netrange = ntohs(atif->nets.nr_lastnet) -
294 ntohs(atif->nets.nr_firstnet) + 1;
295 /* we probe the interface's network */
296 int probe_net = ntohs(atif->address.s_net);
297 int probe_node = ATADDR_ANYNODE; /* we'll take anything */
298 int netct, nodect;
299
300 /* Offset the network we start probing with */
301 if (probe_net == ATADDR_ANYNET) {
302 probe_net = ntohs(atif->nets.nr_firstnet);
303 if (netrange)
304 probe_net += jiffies % netrange;
305 }
306
307 if (probe_node == ATADDR_ANYNODE)
308 probe_node = jiffies & 0xFF;
309
310 /* Scan the networks */
311 for (netct = 0; netct <= netrange; netct++) {
312 /* Sweep the available nodes from a given start */
313 proxy_addr->s_net = htons(probe_net);
314 for (nodect = 0; nodect < 256; nodect++) {
315 proxy_addr->s_node = (nodect + probe_node) & 0xFF;
316 if (proxy_addr->s_node > 0 &&
317 proxy_addr->s_node < 254) {
318 /* Tell AARP to probe a proposed address */
319 int ret = aarp_proxy_probe_network(atif,
320 proxy_addr);
321
322 if (ret != -EADDRINUSE)
323 return ret;
324 }
325 }
326 probe_net++;
327 if (probe_net > ntohs(atif->nets.nr_lastnet))
328 probe_net = ntohs(atif->nets.nr_firstnet);
329 }
330
331 return -EADDRINUSE; /* Network is full... */
332 }
333
334
atalk_find_dev_addr(struct net_device * dev)335 struct atalk_addr *atalk_find_dev_addr(struct net_device *dev)
336 {
337 struct atalk_iface *iface = dev->atalk_ptr;
338 return iface ? &iface->address : NULL;
339 }
340
atalk_find_primary(void)341 static struct atalk_addr *atalk_find_primary(void)
342 {
343 struct atalk_iface *fiface = NULL;
344 struct atalk_addr *retval;
345 struct atalk_iface *iface;
346
347 /*
348 * Return a point-to-point interface only if
349 * there is no non-ptp interface available.
350 */
351 read_lock_bh(&atalk_interfaces_lock);
352 for (iface = atalk_interfaces; iface; iface = iface->next) {
353 if (!fiface && !(iface->dev->flags & IFF_LOOPBACK))
354 fiface = iface;
355 if (!(iface->dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT))) {
356 retval = &iface->address;
357 goto out;
358 }
359 }
360
361 if (fiface)
362 retval = &fiface->address;
363 else if (atalk_interfaces)
364 retval = &atalk_interfaces->address;
365 else
366 retval = NULL;
367 out:
368 read_unlock_bh(&atalk_interfaces_lock);
369 return retval;
370 }
371
372 /*
373 * Find a match for 'any network' - ie any of our interfaces with that
374 * node number will do just nicely.
375 */
atalk_find_anynet(int node,struct net_device * dev)376 static struct atalk_iface *atalk_find_anynet(int node, struct net_device *dev)
377 {
378 struct atalk_iface *iface = dev->atalk_ptr;
379
380 if (!iface || iface->status & ATIF_PROBE)
381 goto out_err;
382
383 if (node != ATADDR_BCAST &&
384 iface->address.s_node != node &&
385 node != ATADDR_ANYNODE)
386 goto out_err;
387 out:
388 return iface;
389 out_err:
390 iface = NULL;
391 goto out;
392 }
393
394 /* Find a match for a specific network:node pair */
atalk_find_interface(__be16 net,int node)395 static struct atalk_iface *atalk_find_interface(__be16 net, int node)
396 {
397 struct atalk_iface *iface;
398
399 read_lock_bh(&atalk_interfaces_lock);
400 for (iface = atalk_interfaces; iface; iface = iface->next) {
401 if ((node == ATADDR_BCAST ||
402 node == ATADDR_ANYNODE ||
403 iface->address.s_node == node) &&
404 iface->address.s_net == net &&
405 !(iface->status & ATIF_PROBE))
406 break;
407
408 /* XXXX.0 -- net.0 returns the iface associated with net */
409 if (node == ATADDR_ANYNODE && net != ATADDR_ANYNET &&
410 ntohs(iface->nets.nr_firstnet) <= ntohs(net) &&
411 ntohs(net) <= ntohs(iface->nets.nr_lastnet))
412 break;
413 }
414 read_unlock_bh(&atalk_interfaces_lock);
415 return iface;
416 }
417
418
419 /*
420 * Find a route for an AppleTalk packet. This ought to get cached in
421 * the socket (later on...). We know about host routes and the fact
422 * that a route must be direct to broadcast.
423 */
atrtr_find(struct atalk_addr * target)424 static struct atalk_route *atrtr_find(struct atalk_addr *target)
425 {
426 /*
427 * we must search through all routes unless we find a
428 * host route, because some host routes might overlap
429 * network routes
430 */
431 struct atalk_route *net_route = NULL;
432 struct atalk_route *r;
433
434 read_lock_bh(&atalk_routes_lock);
435 for (r = atalk_routes; r; r = r->next) {
436 if (!(r->flags & RTF_UP))
437 continue;
438
439 if (r->target.s_net == target->s_net) {
440 if (r->flags & RTF_HOST) {
441 /*
442 * if this host route is for the target,
443 * the we're done
444 */
445 if (r->target.s_node == target->s_node)
446 goto out;
447 } else
448 /*
449 * this route will work if there isn't a
450 * direct host route, so cache it
451 */
452 net_route = r;
453 }
454 }
455
456 /*
457 * if we found a network route but not a direct host
458 * route, then return it
459 */
460 if (net_route)
461 r = net_route;
462 else if (atrtr_default.dev)
463 r = &atrtr_default;
464 else /* No route can be found */
465 r = NULL;
466 out:
467 read_unlock_bh(&atalk_routes_lock);
468 return r;
469 }
470
471
472 /*
473 * Given an AppleTalk network, find the device to use. This can be
474 * a simple lookup.
475 */
atrtr_get_dev(struct atalk_addr * sa)476 struct net_device *atrtr_get_dev(struct atalk_addr *sa)
477 {
478 struct atalk_route *atr = atrtr_find(sa);
479 return atr ? atr->dev : NULL;
480 }
481
482 /* Set up a default router */
atrtr_set_default(struct net_device * dev)483 static void atrtr_set_default(struct net_device *dev)
484 {
485 atrtr_default.dev = dev;
486 atrtr_default.flags = RTF_UP;
487 atrtr_default.gateway.s_net = htons(0);
488 atrtr_default.gateway.s_node = 0;
489 }
490
491 /*
492 * Add a router. Basically make sure it looks valid and stuff the
493 * entry in the list. While it uses netranges we always set them to one
494 * entry to work like netatalk.
495 */
atrtr_create(struct rtentry * r,struct net_device * devhint)496 static int atrtr_create(struct rtentry *r, struct net_device *devhint)
497 {
498 struct sockaddr_at *ta = (struct sockaddr_at *)&r->rt_dst;
499 struct sockaddr_at *ga = (struct sockaddr_at *)&r->rt_gateway;
500 struct atalk_route *rt;
501 struct atalk_iface *iface, *riface;
502 int retval = -EINVAL;
503
504 /*
505 * Fixme: Raise/Lower a routing change semaphore for these
506 * operations.
507 */
508
509 /* Validate the request */
510 if (ta->sat_family != AF_APPLETALK ||
511 (!devhint && ga->sat_family != AF_APPLETALK))
512 goto out;
513
514 /* Now walk the routing table and make our decisions */
515 write_lock_bh(&atalk_routes_lock);
516 for (rt = atalk_routes; rt; rt = rt->next) {
517 if (r->rt_flags != rt->flags)
518 continue;
519
520 if (ta->sat_addr.s_net == rt->target.s_net) {
521 if (!(rt->flags & RTF_HOST))
522 break;
523 if (ta->sat_addr.s_node == rt->target.s_node)
524 break;
525 }
526 }
527
528 if (!devhint) {
529 riface = NULL;
530
531 read_lock_bh(&atalk_interfaces_lock);
532 for (iface = atalk_interfaces; iface; iface = iface->next) {
533 if (!riface &&
534 ntohs(ga->sat_addr.s_net) >=
535 ntohs(iface->nets.nr_firstnet) &&
536 ntohs(ga->sat_addr.s_net) <=
537 ntohs(iface->nets.nr_lastnet))
538 riface = iface;
539
540 if (ga->sat_addr.s_net == iface->address.s_net &&
541 ga->sat_addr.s_node == iface->address.s_node)
542 riface = iface;
543 }
544 read_unlock_bh(&atalk_interfaces_lock);
545
546 retval = -ENETUNREACH;
547 if (!riface)
548 goto out_unlock;
549
550 devhint = riface->dev;
551 }
552
553 if (!rt) {
554 rt = kzalloc(sizeof(*rt), GFP_ATOMIC);
555
556 retval = -ENOBUFS;
557 if (!rt)
558 goto out_unlock;
559
560 rt->next = atalk_routes;
561 atalk_routes = rt;
562 }
563
564 /* Fill in the routing entry */
565 rt->target = ta->sat_addr;
566 dev_put(rt->dev); /* Release old device */
567 dev_hold(devhint);
568 rt->dev = devhint;
569 rt->flags = r->rt_flags;
570 rt->gateway = ga->sat_addr;
571
572 retval = 0;
573 out_unlock:
574 write_unlock_bh(&atalk_routes_lock);
575 out:
576 return retval;
577 }
578
579 /* Delete a route. Find it and discard it */
atrtr_delete(struct atalk_addr * addr)580 static int atrtr_delete(struct atalk_addr *addr)
581 {
582 struct atalk_route **r = &atalk_routes;
583 int retval = 0;
584 struct atalk_route *tmp;
585
586 write_lock_bh(&atalk_routes_lock);
587 while ((tmp = *r) != NULL) {
588 if (tmp->target.s_net == addr->s_net &&
589 (!(tmp->flags&RTF_GATEWAY) ||
590 tmp->target.s_node == addr->s_node)) {
591 *r = tmp->next;
592 dev_put(tmp->dev);
593 kfree(tmp);
594 goto out;
595 }
596 r = &tmp->next;
597 }
598 retval = -ENOENT;
599 out:
600 write_unlock_bh(&atalk_routes_lock);
601 return retval;
602 }
603
604 /*
605 * Called when a device is downed. Just throw away any routes
606 * via it.
607 */
atrtr_device_down(struct net_device * dev)608 static void atrtr_device_down(struct net_device *dev)
609 {
610 struct atalk_route **r = &atalk_routes;
611 struct atalk_route *tmp;
612
613 write_lock_bh(&atalk_routes_lock);
614 while ((tmp = *r) != NULL) {
615 if (tmp->dev == dev) {
616 *r = tmp->next;
617 dev_put(dev);
618 kfree(tmp);
619 } else
620 r = &tmp->next;
621 }
622 write_unlock_bh(&atalk_routes_lock);
623
624 if (atrtr_default.dev == dev)
625 atrtr_set_default(NULL);
626 }
627
628 /* Actually down the interface */
atalk_dev_down(struct net_device * dev)629 static inline void atalk_dev_down(struct net_device *dev)
630 {
631 atrtr_device_down(dev); /* Remove all routes for the device */
632 aarp_device_down(dev); /* Remove AARP entries for the device */
633 atif_drop_device(dev); /* Remove the device */
634 }
635
636 /*
637 * A device event has occurred. Watch for devices going down and
638 * delete our use of them (iface and route).
639 */
ddp_device_event(struct notifier_block * this,unsigned long event,void * ptr)640 static int ddp_device_event(struct notifier_block *this, unsigned long event,
641 void *ptr)
642 {
643 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
644
645 if (!net_eq(dev_net(dev), &init_net))
646 return NOTIFY_DONE;
647
648 if (event == NETDEV_DOWN)
649 /* Discard any use of this */
650 atalk_dev_down(dev);
651
652 return NOTIFY_DONE;
653 }
654
655 /* ioctl calls. Shouldn't even need touching */
656 /* Device configuration ioctl calls */
atif_ioctl(int cmd,void __user * arg)657 static int atif_ioctl(int cmd, void __user *arg)
658 {
659 static char aarp_mcast[6] = { 0x09, 0x00, 0x00, 0xFF, 0xFF, 0xFF };
660 struct ifreq atreq;
661 struct atalk_netrange *nr;
662 struct sockaddr_at *sa;
663 struct net_device *dev;
664 struct atalk_iface *atif;
665 int ct;
666 int limit;
667 struct rtentry rtdef;
668 int add_route;
669
670 if (get_user_ifreq(&atreq, NULL, arg))
671 return -EFAULT;
672
673 dev = __dev_get_by_name(&init_net, atreq.ifr_name);
674 if (!dev)
675 return -ENODEV;
676
677 sa = (struct sockaddr_at *)&atreq.ifr_addr;
678 atif = atalk_find_dev(dev);
679
680 switch (cmd) {
681 case SIOCSIFADDR:
682 if (!capable(CAP_NET_ADMIN))
683 return -EPERM;
684 if (sa->sat_family != AF_APPLETALK)
685 return -EINVAL;
686 if (dev->type != ARPHRD_ETHER &&
687 dev->type != ARPHRD_LOOPBACK &&
688 dev->type != ARPHRD_LOCALTLK &&
689 dev->type != ARPHRD_PPP)
690 return -EPROTONOSUPPORT;
691
692 nr = (struct atalk_netrange *)&sa->sat_zero[0];
693 add_route = 1;
694
695 /*
696 * if this is a point-to-point iface, and we already
697 * have an iface for this AppleTalk address, then we
698 * should not add a route
699 */
700 if ((dev->flags & IFF_POINTOPOINT) &&
701 atalk_find_interface(sa->sat_addr.s_net,
702 sa->sat_addr.s_node)) {
703 printk(KERN_DEBUG "AppleTalk: point-to-point "
704 "interface added with "
705 "existing address\n");
706 add_route = 0;
707 }
708
709 /*
710 * Phase 1 is fine on LocalTalk but we don't do
711 * EtherTalk phase 1. Anyone wanting to add it, go ahead.
712 */
713 if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
714 return -EPROTONOSUPPORT;
715 if (sa->sat_addr.s_node == ATADDR_BCAST ||
716 sa->sat_addr.s_node == 254)
717 return -EINVAL;
718 if (atif) {
719 /* Already setting address */
720 if (atif->status & ATIF_PROBE)
721 return -EBUSY;
722
723 atif->address.s_net = sa->sat_addr.s_net;
724 atif->address.s_node = sa->sat_addr.s_node;
725 atrtr_device_down(dev); /* Flush old routes */
726 } else {
727 atif = atif_add_device(dev, &sa->sat_addr);
728 if (!atif)
729 return -ENOMEM;
730 }
731 atif->nets = *nr;
732
733 /*
734 * Check if the chosen address is used. If so we
735 * error and atalkd will try another.
736 */
737
738 if (!(dev->flags & IFF_LOOPBACK) &&
739 !(dev->flags & IFF_POINTOPOINT) &&
740 atif_probe_device(atif) < 0) {
741 atif_drop_device(dev);
742 return -EADDRINUSE;
743 }
744
745 /* Hey it worked - add the direct routes */
746 sa = (struct sockaddr_at *)&rtdef.rt_gateway;
747 sa->sat_family = AF_APPLETALK;
748 sa->sat_addr.s_net = atif->address.s_net;
749 sa->sat_addr.s_node = atif->address.s_node;
750 sa = (struct sockaddr_at *)&rtdef.rt_dst;
751 rtdef.rt_flags = RTF_UP;
752 sa->sat_family = AF_APPLETALK;
753 sa->sat_addr.s_node = ATADDR_ANYNODE;
754 if (dev->flags & IFF_LOOPBACK ||
755 dev->flags & IFF_POINTOPOINT)
756 rtdef.rt_flags |= RTF_HOST;
757
758 /* Routerless initial state */
759 if (nr->nr_firstnet == htons(0) &&
760 nr->nr_lastnet == htons(0xFFFE)) {
761 sa->sat_addr.s_net = atif->address.s_net;
762 atrtr_create(&rtdef, dev);
763 atrtr_set_default(dev);
764 } else {
765 limit = ntohs(nr->nr_lastnet);
766 if (limit - ntohs(nr->nr_firstnet) > 4096) {
767 printk(KERN_WARNING "Too many routes/"
768 "iface.\n");
769 return -EINVAL;
770 }
771 if (add_route)
772 for (ct = ntohs(nr->nr_firstnet);
773 ct <= limit; ct++) {
774 sa->sat_addr.s_net = htons(ct);
775 atrtr_create(&rtdef, dev);
776 }
777 }
778 dev_mc_add_global(dev, aarp_mcast);
779 return 0;
780
781 case SIOCGIFADDR:
782 if (!atif)
783 return -EADDRNOTAVAIL;
784
785 sa->sat_family = AF_APPLETALK;
786 sa->sat_addr = atif->address;
787 break;
788
789 case SIOCGIFBRDADDR:
790 if (!atif)
791 return -EADDRNOTAVAIL;
792
793 sa->sat_family = AF_APPLETALK;
794 sa->sat_addr.s_net = atif->address.s_net;
795 sa->sat_addr.s_node = ATADDR_BCAST;
796 break;
797
798 case SIOCATALKDIFADDR:
799 case SIOCDIFADDR:
800 if (!capable(CAP_NET_ADMIN))
801 return -EPERM;
802 if (sa->sat_family != AF_APPLETALK)
803 return -EINVAL;
804 atalk_dev_down(dev);
805 break;
806
807 case SIOCSARP:
808 if (!capable(CAP_NET_ADMIN))
809 return -EPERM;
810 if (sa->sat_family != AF_APPLETALK)
811 return -EINVAL;
812 /*
813 * for now, we only support proxy AARP on ELAP;
814 * we should be able to do it for LocalTalk, too.
815 */
816 if (dev->type != ARPHRD_ETHER)
817 return -EPROTONOSUPPORT;
818
819 /*
820 * atif points to the current interface on this network;
821 * we aren't concerned about its current status (at
822 * least for now), but it has all the settings about
823 * the network we're going to probe. Consequently, it
824 * must exist.
825 */
826 if (!atif)
827 return -EADDRNOTAVAIL;
828
829 nr = (struct atalk_netrange *)&(atif->nets);
830 /*
831 * Phase 1 is fine on Localtalk but we don't do
832 * Ethertalk phase 1. Anyone wanting to add it, go ahead.
833 */
834 if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
835 return -EPROTONOSUPPORT;
836
837 if (sa->sat_addr.s_node == ATADDR_BCAST ||
838 sa->sat_addr.s_node == 254)
839 return -EINVAL;
840
841 /*
842 * Check if the chosen address is used. If so we
843 * error and ATCP will try another.
844 */
845 if (atif_proxy_probe_device(atif, &(sa->sat_addr)) < 0)
846 return -EADDRINUSE;
847
848 /*
849 * We now have an address on the local network, and
850 * the AARP code will defend it for us until we take it
851 * down. We don't set up any routes right now, because
852 * ATCP will install them manually via SIOCADDRT.
853 */
854 break;
855
856 case SIOCDARP:
857 if (!capable(CAP_NET_ADMIN))
858 return -EPERM;
859 if (sa->sat_family != AF_APPLETALK)
860 return -EINVAL;
861 if (!atif)
862 return -EADDRNOTAVAIL;
863
864 /* give to aarp module to remove proxy entry */
865 aarp_proxy_remove(atif->dev, &(sa->sat_addr));
866 return 0;
867 }
868
869 return put_user_ifreq(&atreq, arg);
870 }
871
atrtr_ioctl_addrt(struct rtentry * rt)872 static int atrtr_ioctl_addrt(struct rtentry *rt)
873 {
874 struct net_device *dev = NULL;
875
876 if (rt->rt_dev) {
877 char name[IFNAMSIZ];
878
879 if (copy_from_user(name, rt->rt_dev, IFNAMSIZ-1))
880 return -EFAULT;
881 name[IFNAMSIZ-1] = '\0';
882
883 dev = __dev_get_by_name(&init_net, name);
884 if (!dev)
885 return -ENODEV;
886 }
887 return atrtr_create(rt, dev);
888 }
889
890 /* Routing ioctl() calls */
atrtr_ioctl(unsigned int cmd,void __user * arg)891 static int atrtr_ioctl(unsigned int cmd, void __user *arg)
892 {
893 struct rtentry rt;
894
895 if (copy_from_user(&rt, arg, sizeof(rt)))
896 return -EFAULT;
897
898 switch (cmd) {
899 case SIOCDELRT:
900 if (rt.rt_dst.sa_family != AF_APPLETALK)
901 return -EINVAL;
902 return atrtr_delete(&((struct sockaddr_at *)
903 &rt.rt_dst)->sat_addr);
904
905 case SIOCADDRT:
906 return atrtr_ioctl_addrt(&rt);
907 }
908 return -EINVAL;
909 }
910
911 /**************************************************************************\
912 * *
913 * Handling for system calls applied via the various interfaces to an *
914 * AppleTalk socket object. *
915 * *
916 \**************************************************************************/
917
918 /*
919 * Checksum: This is 'optional'. It's quite likely also a good
920 * candidate for assembler hackery 8)
921 */
atalk_sum_partial(const unsigned char * data,int len,unsigned long sum)922 static unsigned long atalk_sum_partial(const unsigned char *data,
923 int len, unsigned long sum)
924 {
925 /* This ought to be unwrapped neatly. I'll trust gcc for now */
926 while (len--) {
927 sum += *data++;
928 sum = rol16(sum, 1);
929 }
930 return sum;
931 }
932
933 /* Checksum skb data -- similar to skb_checksum */
atalk_sum_skb(const struct sk_buff * skb,int offset,int len,unsigned long sum)934 static unsigned long atalk_sum_skb(const struct sk_buff *skb, int offset,
935 int len, unsigned long sum)
936 {
937 int start = skb_headlen(skb);
938 struct sk_buff *frag_iter;
939 int i, copy;
940
941 /* checksum stuff in header space */
942 if ((copy = start - offset) > 0) {
943 if (copy > len)
944 copy = len;
945 sum = atalk_sum_partial(skb->data + offset, copy, sum);
946 if ((len -= copy) == 0)
947 return sum;
948
949 offset += copy;
950 }
951
952 /* checksum stuff in frags */
953 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
954 int end;
955 const skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
956 WARN_ON(start > offset + len);
957
958 end = start + skb_frag_size(frag);
959 if ((copy = end - offset) > 0) {
960 u8 *vaddr;
961
962 if (copy > len)
963 copy = len;
964 vaddr = kmap_atomic(skb_frag_page(frag));
965 sum = atalk_sum_partial(vaddr + skb_frag_off(frag) +
966 offset - start, copy, sum);
967 kunmap_atomic(vaddr);
968
969 if (!(len -= copy))
970 return sum;
971 offset += copy;
972 }
973 start = end;
974 }
975
976 skb_walk_frags(skb, frag_iter) {
977 int end;
978
979 WARN_ON(start > offset + len);
980
981 end = start + frag_iter->len;
982 if ((copy = end - offset) > 0) {
983 if (copy > len)
984 copy = len;
985 sum = atalk_sum_skb(frag_iter, offset - start,
986 copy, sum);
987 if ((len -= copy) == 0)
988 return sum;
989 offset += copy;
990 }
991 start = end;
992 }
993
994 BUG_ON(len > 0);
995
996 return sum;
997 }
998
atalk_checksum(const struct sk_buff * skb,int len)999 static __be16 atalk_checksum(const struct sk_buff *skb, int len)
1000 {
1001 unsigned long sum;
1002
1003 /* skip header 4 bytes */
1004 sum = atalk_sum_skb(skb, 4, len-4, 0);
1005
1006 /* Use 0xFFFF for 0. 0 itself means none */
1007 return sum ? htons((unsigned short)sum) : htons(0xFFFF);
1008 }
1009
1010 static struct proto ddp_proto = {
1011 .name = "DDP",
1012 .owner = THIS_MODULE,
1013 .obj_size = sizeof(struct atalk_sock),
1014 };
1015
1016 /*
1017 * Create a socket. Initialise the socket, blank the addresses
1018 * set the state.
1019 */
atalk_create(struct net * net,struct socket * sock,int protocol,int kern)1020 static int atalk_create(struct net *net, struct socket *sock, int protocol,
1021 int kern)
1022 {
1023 struct sock *sk;
1024 int rc = -ESOCKTNOSUPPORT;
1025
1026 if (!net_eq(net, &init_net))
1027 return -EAFNOSUPPORT;
1028
1029 /*
1030 * We permit SOCK_DGRAM and RAW is an extension. It is trivial to do
1031 * and gives you the full ELAP frame. Should be handy for CAP 8)
1032 */
1033 if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
1034 goto out;
1035
1036 rc = -EPERM;
1037 if (sock->type == SOCK_RAW && !kern && !capable(CAP_NET_RAW))
1038 goto out;
1039
1040 rc = -ENOMEM;
1041 sk = sk_alloc(net, PF_APPLETALK, GFP_KERNEL, &ddp_proto, kern);
1042 if (!sk)
1043 goto out;
1044 rc = 0;
1045 sock->ops = &atalk_dgram_ops;
1046 sock_init_data(sock, sk);
1047
1048 /* Checksums on by default */
1049 sock_set_flag(sk, SOCK_ZAPPED);
1050 out:
1051 return rc;
1052 }
1053
1054 /* Free a socket. No work needed */
atalk_release(struct socket * sock)1055 static int atalk_release(struct socket *sock)
1056 {
1057 struct sock *sk = sock->sk;
1058
1059 if (sk) {
1060 sock_hold(sk);
1061 lock_sock(sk);
1062
1063 sock_orphan(sk);
1064 sock->sk = NULL;
1065 atalk_destroy_socket(sk);
1066
1067 release_sock(sk);
1068 sock_put(sk);
1069 }
1070 return 0;
1071 }
1072
1073 /**
1074 * atalk_pick_and_bind_port - Pick a source port when one is not given
1075 * @sk: socket to insert into the tables
1076 * @sat: address to search for
1077 *
1078 * Pick a source port when one is not given. If we can find a suitable free
1079 * one, we insert the socket into the tables using it.
1080 *
1081 * This whole operation must be atomic.
1082 */
atalk_pick_and_bind_port(struct sock * sk,struct sockaddr_at * sat)1083 static int atalk_pick_and_bind_port(struct sock *sk, struct sockaddr_at *sat)
1084 {
1085 int retval;
1086
1087 write_lock_bh(&atalk_sockets_lock);
1088
1089 for (sat->sat_port = ATPORT_RESERVED;
1090 sat->sat_port < ATPORT_LAST;
1091 sat->sat_port++) {
1092 struct sock *s;
1093
1094 sk_for_each(s, &atalk_sockets) {
1095 struct atalk_sock *at = at_sk(s);
1096
1097 if (at->src_net == sat->sat_addr.s_net &&
1098 at->src_node == sat->sat_addr.s_node &&
1099 at->src_port == sat->sat_port)
1100 goto try_next_port;
1101 }
1102
1103 /* Wheee, it's free, assign and insert. */
1104 __atalk_insert_socket(sk);
1105 at_sk(sk)->src_port = sat->sat_port;
1106 retval = 0;
1107 goto out;
1108
1109 try_next_port:;
1110 }
1111
1112 retval = -EBUSY;
1113 out:
1114 write_unlock_bh(&atalk_sockets_lock);
1115 return retval;
1116 }
1117
atalk_autobind(struct sock * sk)1118 static int atalk_autobind(struct sock *sk)
1119 {
1120 struct atalk_sock *at = at_sk(sk);
1121 struct sockaddr_at sat;
1122 struct atalk_addr *ap = atalk_find_primary();
1123 int n = -EADDRNOTAVAIL;
1124
1125 if (!ap || ap->s_net == htons(ATADDR_ANYNET))
1126 goto out;
1127
1128 at->src_net = sat.sat_addr.s_net = ap->s_net;
1129 at->src_node = sat.sat_addr.s_node = ap->s_node;
1130
1131 n = atalk_pick_and_bind_port(sk, &sat);
1132 if (!n)
1133 sock_reset_flag(sk, SOCK_ZAPPED);
1134 out:
1135 return n;
1136 }
1137
1138 /* Set the address 'our end' of the connection */
atalk_bind(struct socket * sock,struct sockaddr * uaddr,int addr_len)1139 static int atalk_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
1140 {
1141 struct sockaddr_at *addr = (struct sockaddr_at *)uaddr;
1142 struct sock *sk = sock->sk;
1143 struct atalk_sock *at = at_sk(sk);
1144 int err;
1145
1146 if (!sock_flag(sk, SOCK_ZAPPED) ||
1147 addr_len != sizeof(struct sockaddr_at))
1148 return -EINVAL;
1149
1150 if (addr->sat_family != AF_APPLETALK)
1151 return -EAFNOSUPPORT;
1152
1153 lock_sock(sk);
1154 if (addr->sat_addr.s_net == htons(ATADDR_ANYNET)) {
1155 struct atalk_addr *ap = atalk_find_primary();
1156
1157 err = -EADDRNOTAVAIL;
1158 if (!ap)
1159 goto out;
1160
1161 at->src_net = addr->sat_addr.s_net = ap->s_net;
1162 at->src_node = addr->sat_addr.s_node = ap->s_node;
1163 } else {
1164 err = -EADDRNOTAVAIL;
1165 if (!atalk_find_interface(addr->sat_addr.s_net,
1166 addr->sat_addr.s_node))
1167 goto out;
1168
1169 at->src_net = addr->sat_addr.s_net;
1170 at->src_node = addr->sat_addr.s_node;
1171 }
1172
1173 if (addr->sat_port == ATADDR_ANYPORT) {
1174 err = atalk_pick_and_bind_port(sk, addr);
1175
1176 if (err < 0)
1177 goto out;
1178 } else {
1179 at->src_port = addr->sat_port;
1180
1181 err = -EADDRINUSE;
1182 if (atalk_find_or_insert_socket(sk, addr))
1183 goto out;
1184 }
1185
1186 sock_reset_flag(sk, SOCK_ZAPPED);
1187 err = 0;
1188 out:
1189 release_sock(sk);
1190 return err;
1191 }
1192
1193 /* Set the address we talk to */
atalk_connect(struct socket * sock,struct sockaddr * uaddr,int addr_len,int flags)1194 static int atalk_connect(struct socket *sock, struct sockaddr *uaddr,
1195 int addr_len, int flags)
1196 {
1197 struct sock *sk = sock->sk;
1198 struct atalk_sock *at = at_sk(sk);
1199 struct sockaddr_at *addr;
1200 int err;
1201
1202 sk->sk_state = TCP_CLOSE;
1203 sock->state = SS_UNCONNECTED;
1204
1205 if (addr_len != sizeof(*addr))
1206 return -EINVAL;
1207
1208 addr = (struct sockaddr_at *)uaddr;
1209
1210 if (addr->sat_family != AF_APPLETALK)
1211 return -EAFNOSUPPORT;
1212
1213 if (addr->sat_addr.s_node == ATADDR_BCAST &&
1214 !sock_flag(sk, SOCK_BROADCAST)) {
1215 #if 1
1216 pr_warn("atalk_connect: %s is broken and did not set SO_BROADCAST.\n",
1217 current->comm);
1218 #else
1219 return -EACCES;
1220 #endif
1221 }
1222
1223 lock_sock(sk);
1224 err = -EBUSY;
1225 if (sock_flag(sk, SOCK_ZAPPED))
1226 if (atalk_autobind(sk) < 0)
1227 goto out;
1228
1229 err = -ENETUNREACH;
1230 if (!atrtr_get_dev(&addr->sat_addr))
1231 goto out;
1232
1233 at->dest_port = addr->sat_port;
1234 at->dest_net = addr->sat_addr.s_net;
1235 at->dest_node = addr->sat_addr.s_node;
1236
1237 sock->state = SS_CONNECTED;
1238 sk->sk_state = TCP_ESTABLISHED;
1239 err = 0;
1240 out:
1241 release_sock(sk);
1242 return err;
1243 }
1244
1245 /*
1246 * Find the name of an AppleTalk socket. Just copy the right
1247 * fields into the sockaddr.
1248 */
atalk_getname(struct socket * sock,struct sockaddr * uaddr,int peer)1249 static int atalk_getname(struct socket *sock, struct sockaddr *uaddr,
1250 int peer)
1251 {
1252 struct sockaddr_at sat;
1253 struct sock *sk = sock->sk;
1254 struct atalk_sock *at = at_sk(sk);
1255 int err;
1256
1257 lock_sock(sk);
1258 err = -ENOBUFS;
1259 if (sock_flag(sk, SOCK_ZAPPED))
1260 if (atalk_autobind(sk) < 0)
1261 goto out;
1262
1263 memset(&sat, 0, sizeof(sat));
1264
1265 if (peer) {
1266 err = -ENOTCONN;
1267 if (sk->sk_state != TCP_ESTABLISHED)
1268 goto out;
1269
1270 sat.sat_addr.s_net = at->dest_net;
1271 sat.sat_addr.s_node = at->dest_node;
1272 sat.sat_port = at->dest_port;
1273 } else {
1274 sat.sat_addr.s_net = at->src_net;
1275 sat.sat_addr.s_node = at->src_node;
1276 sat.sat_port = at->src_port;
1277 }
1278
1279 sat.sat_family = AF_APPLETALK;
1280 memcpy(uaddr, &sat, sizeof(sat));
1281 err = sizeof(struct sockaddr_at);
1282
1283 out:
1284 release_sock(sk);
1285 return err;
1286 }
1287
1288 #if IS_ENABLED(CONFIG_IPDDP)
is_ip_over_ddp(struct sk_buff * skb)1289 static __inline__ int is_ip_over_ddp(struct sk_buff *skb)
1290 {
1291 return skb->data[12] == 22;
1292 }
1293
handle_ip_over_ddp(struct sk_buff * skb)1294 static int handle_ip_over_ddp(struct sk_buff *skb)
1295 {
1296 struct net_device *dev = __dev_get_by_name(&init_net, "ipddp0");
1297 struct net_device_stats *stats;
1298
1299 /* This needs to be able to handle ipddp"N" devices */
1300 if (!dev) {
1301 kfree_skb(skb);
1302 return NET_RX_DROP;
1303 }
1304
1305 skb->protocol = htons(ETH_P_IP);
1306 skb_pull(skb, 13);
1307 skb->dev = dev;
1308 skb_reset_transport_header(skb);
1309
1310 stats = netdev_priv(dev);
1311 stats->rx_packets++;
1312 stats->rx_bytes += skb->len + 13;
1313 return netif_rx(skb); /* Send the SKB up to a higher place. */
1314 }
1315 #else
1316 /* make it easy for gcc to optimize this test out, i.e. kill the code */
1317 #define is_ip_over_ddp(skb) 0
1318 #define handle_ip_over_ddp(skb) 0
1319 #endif
1320
atalk_route_packet(struct sk_buff * skb,struct net_device * dev,struct ddpehdr * ddp,__u16 len_hops,int origlen)1321 static int atalk_route_packet(struct sk_buff *skb, struct net_device *dev,
1322 struct ddpehdr *ddp, __u16 len_hops, int origlen)
1323 {
1324 struct atalk_route *rt;
1325 struct atalk_addr ta;
1326
1327 /*
1328 * Don't route multicast, etc., packets, or packets sent to "this
1329 * network"
1330 */
1331 if (skb->pkt_type != PACKET_HOST || !ddp->deh_dnet) {
1332 /*
1333 * FIXME:
1334 *
1335 * Can it ever happen that a packet is from a PPP iface and
1336 * needs to be broadcast onto the default network?
1337 */
1338 if (dev->type == ARPHRD_PPP)
1339 printk(KERN_DEBUG "AppleTalk: didn't forward broadcast "
1340 "packet received from PPP iface\n");
1341 goto free_it;
1342 }
1343
1344 ta.s_net = ddp->deh_dnet;
1345 ta.s_node = ddp->deh_dnode;
1346
1347 /* Route the packet */
1348 rt = atrtr_find(&ta);
1349 /* increment hops count */
1350 len_hops += 1 << 10;
1351 if (!rt || !(len_hops & (15 << 10)))
1352 goto free_it;
1353
1354 /* FIXME: use skb->cb to be able to use shared skbs */
1355
1356 /*
1357 * Route goes through another gateway, so set the target to the
1358 * gateway instead.
1359 */
1360
1361 if (rt->flags & RTF_GATEWAY) {
1362 ta.s_net = rt->gateway.s_net;
1363 ta.s_node = rt->gateway.s_node;
1364 }
1365
1366 /* Fix up skb->len field */
1367 skb_trim(skb, min_t(unsigned int, origlen,
1368 (rt->dev->hard_header_len +
1369 ddp_dl->header_length + (len_hops & 1023))));
1370
1371 /* FIXME: use skb->cb to be able to use shared skbs */
1372 ddp->deh_len_hops = htons(len_hops);
1373
1374 /*
1375 * Send the buffer onwards
1376 *
1377 * Now we must always be careful. If it's come from LocalTalk to
1378 * EtherTalk it might not fit
1379 *
1380 * Order matters here: If a packet has to be copied to make a new
1381 * headroom (rare hopefully) then it won't need unsharing.
1382 *
1383 * Note. ddp-> becomes invalid at the realloc.
1384 */
1385 if (skb_headroom(skb) < 22) {
1386 /* 22 bytes - 12 ether, 2 len, 3 802.2 5 snap */
1387 struct sk_buff *nskb = skb_realloc_headroom(skb, 32);
1388 kfree_skb(skb);
1389 skb = nskb;
1390 } else
1391 skb = skb_unshare(skb, GFP_ATOMIC);
1392
1393 /*
1394 * If the buffer didn't vanish into the lack of space bitbucket we can
1395 * send it.
1396 */
1397 if (skb == NULL)
1398 goto drop;
1399
1400 if (aarp_send_ddp(rt->dev, skb, &ta, NULL) == NET_XMIT_DROP)
1401 return NET_RX_DROP;
1402 return NET_RX_SUCCESS;
1403 free_it:
1404 kfree_skb(skb);
1405 drop:
1406 return NET_RX_DROP;
1407 }
1408
1409 /**
1410 * atalk_rcv - Receive a packet (in skb) from device dev
1411 * @skb: packet received
1412 * @dev: network device where the packet comes from
1413 * @pt: packet type
1414 * @orig_dev: the original receive net device
1415 *
1416 * Receive a packet (in skb) from device dev. This has come from the SNAP
1417 * decoder, and on entry skb->transport_header is the DDP header, skb->len
1418 * is the DDP header, skb->len is the DDP length. The physical headers
1419 * have been extracted. PPP should probably pass frames marked as for this
1420 * layer. [ie ARPHRD_ETHERTALK]
1421 */
atalk_rcv(struct sk_buff * skb,struct net_device * dev,struct packet_type * pt,struct net_device * orig_dev)1422 static int atalk_rcv(struct sk_buff *skb, struct net_device *dev,
1423 struct packet_type *pt, struct net_device *orig_dev)
1424 {
1425 struct ddpehdr *ddp;
1426 struct sock *sock;
1427 struct atalk_iface *atif;
1428 struct sockaddr_at tosat;
1429 int origlen;
1430 __u16 len_hops;
1431
1432 if (!net_eq(dev_net(dev), &init_net))
1433 goto drop;
1434
1435 /* Don't mangle buffer if shared */
1436 if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1437 goto out;
1438
1439 /* Size check and make sure header is contiguous */
1440 if (!pskb_may_pull(skb, sizeof(*ddp)))
1441 goto drop;
1442
1443 ddp = ddp_hdr(skb);
1444
1445 len_hops = ntohs(ddp->deh_len_hops);
1446
1447 /* Trim buffer in case of stray trailing data */
1448 origlen = skb->len;
1449 skb_trim(skb, min_t(unsigned int, skb->len, len_hops & 1023));
1450
1451 /*
1452 * Size check to see if ddp->deh_len was crap
1453 * (Otherwise we'll detonate most spectacularly
1454 * in the middle of atalk_checksum() or recvmsg()).
1455 */
1456 if (skb->len < sizeof(*ddp) || skb->len < (len_hops & 1023)) {
1457 pr_debug("AppleTalk: dropping corrupted frame (deh_len=%u, "
1458 "skb->len=%u)\n", len_hops & 1023, skb->len);
1459 goto drop;
1460 }
1461
1462 /*
1463 * Any checksums. Note we don't do htons() on this == is assumed to be
1464 * valid for net byte orders all over the networking code...
1465 */
1466 if (ddp->deh_sum &&
1467 atalk_checksum(skb, len_hops & 1023) != ddp->deh_sum)
1468 /* Not a valid AppleTalk frame - dustbin time */
1469 goto drop;
1470
1471 /* Check the packet is aimed at us */
1472 if (!ddp->deh_dnet) /* Net 0 is 'this network' */
1473 atif = atalk_find_anynet(ddp->deh_dnode, dev);
1474 else
1475 atif = atalk_find_interface(ddp->deh_dnet, ddp->deh_dnode);
1476
1477 if (!atif) {
1478 /* Not ours, so we route the packet via the correct
1479 * AppleTalk iface
1480 */
1481 return atalk_route_packet(skb, dev, ddp, len_hops, origlen);
1482 }
1483
1484 /* if IP over DDP is not selected this code will be optimized out */
1485 if (is_ip_over_ddp(skb))
1486 return handle_ip_over_ddp(skb);
1487 /*
1488 * Which socket - atalk_search_socket() looks for a *full match*
1489 * of the <net, node, port> tuple.
1490 */
1491 tosat.sat_addr.s_net = ddp->deh_dnet;
1492 tosat.sat_addr.s_node = ddp->deh_dnode;
1493 tosat.sat_port = ddp->deh_dport;
1494
1495 sock = atalk_search_socket(&tosat, atif);
1496 if (!sock) /* But not one of our sockets */
1497 goto drop;
1498
1499 /* Queue packet (standard) */
1500 if (sock_queue_rcv_skb(sock, skb) < 0)
1501 goto drop;
1502
1503 return NET_RX_SUCCESS;
1504
1505 drop:
1506 kfree_skb(skb);
1507 out:
1508 return NET_RX_DROP;
1509
1510 }
1511
1512 /*
1513 * Receive a LocalTalk frame. We make some demands on the caller here.
1514 * Caller must provide enough headroom on the packet to pull the short
1515 * header and append a long one.
1516 */
ltalk_rcv(struct sk_buff * skb,struct net_device * dev,struct packet_type * pt,struct net_device * orig_dev)1517 static int ltalk_rcv(struct sk_buff *skb, struct net_device *dev,
1518 struct packet_type *pt, struct net_device *orig_dev)
1519 {
1520 if (!net_eq(dev_net(dev), &init_net))
1521 goto freeit;
1522
1523 /* Expand any short form frames */
1524 if (skb_mac_header(skb)[2] == 1) {
1525 struct ddpehdr *ddp;
1526 /* Find our address */
1527 struct atalk_addr *ap = atalk_find_dev_addr(dev);
1528
1529 if (!ap || skb->len < sizeof(__be16) || skb->len > 1023)
1530 goto freeit;
1531
1532 /* Don't mangle buffer if shared */
1533 if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1534 return 0;
1535
1536 /*
1537 * The push leaves us with a ddephdr not an shdr, and
1538 * handily the port bytes in the right place preset.
1539 */
1540 ddp = skb_push(skb, sizeof(*ddp) - 4);
1541
1542 /* Now fill in the long header */
1543
1544 /*
1545 * These two first. The mac overlays the new source/dest
1546 * network information so we MUST copy these before
1547 * we write the network numbers !
1548 */
1549
1550 ddp->deh_dnode = skb_mac_header(skb)[0]; /* From physical header */
1551 ddp->deh_snode = skb_mac_header(skb)[1]; /* From physical header */
1552
1553 ddp->deh_dnet = ap->s_net; /* Network number */
1554 ddp->deh_snet = ap->s_net;
1555 ddp->deh_sum = 0; /* No checksum */
1556 /*
1557 * Not sure about this bit...
1558 */
1559 /* Non routable, so force a drop if we slip up later */
1560 ddp->deh_len_hops = htons(skb->len + (DDP_MAXHOPS << 10));
1561 }
1562 skb_reset_transport_header(skb);
1563
1564 return atalk_rcv(skb, dev, pt, orig_dev);
1565 freeit:
1566 kfree_skb(skb);
1567 return 0;
1568 }
1569
atalk_sendmsg(struct socket * sock,struct msghdr * msg,size_t len)1570 static int atalk_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
1571 {
1572 struct sock *sk = sock->sk;
1573 struct atalk_sock *at = at_sk(sk);
1574 DECLARE_SOCKADDR(struct sockaddr_at *, usat, msg->msg_name);
1575 int flags = msg->msg_flags;
1576 int loopback = 0;
1577 struct sockaddr_at local_satalk, gsat;
1578 struct sk_buff *skb;
1579 struct net_device *dev;
1580 struct ddpehdr *ddp;
1581 int size, hard_header_len;
1582 struct atalk_route *rt, *rt_lo = NULL;
1583 int err;
1584
1585 if (flags & ~(MSG_DONTWAIT|MSG_CMSG_COMPAT))
1586 return -EINVAL;
1587
1588 if (len > DDP_MAXSZ)
1589 return -EMSGSIZE;
1590
1591 lock_sock(sk);
1592 if (usat) {
1593 err = -EBUSY;
1594 if (sock_flag(sk, SOCK_ZAPPED))
1595 if (atalk_autobind(sk) < 0)
1596 goto out;
1597
1598 err = -EINVAL;
1599 if (msg->msg_namelen < sizeof(*usat) ||
1600 usat->sat_family != AF_APPLETALK)
1601 goto out;
1602
1603 err = -EPERM;
1604 /* netatalk didn't implement this check */
1605 if (usat->sat_addr.s_node == ATADDR_BCAST &&
1606 !sock_flag(sk, SOCK_BROADCAST)) {
1607 goto out;
1608 }
1609 } else {
1610 err = -ENOTCONN;
1611 if (sk->sk_state != TCP_ESTABLISHED)
1612 goto out;
1613 usat = &local_satalk;
1614 usat->sat_family = AF_APPLETALK;
1615 usat->sat_port = at->dest_port;
1616 usat->sat_addr.s_node = at->dest_node;
1617 usat->sat_addr.s_net = at->dest_net;
1618 }
1619
1620 /* Build a packet */
1621 SOCK_DEBUG(sk, "SK %p: Got address.\n", sk);
1622
1623 /* For headers */
1624 size = sizeof(struct ddpehdr) + len + ddp_dl->header_length;
1625
1626 if (usat->sat_addr.s_net || usat->sat_addr.s_node == ATADDR_ANYNODE) {
1627 rt = atrtr_find(&usat->sat_addr);
1628 } else {
1629 struct atalk_addr at_hint;
1630
1631 at_hint.s_node = 0;
1632 at_hint.s_net = at->src_net;
1633
1634 rt = atrtr_find(&at_hint);
1635 }
1636 err = -ENETUNREACH;
1637 if (!rt)
1638 goto out;
1639
1640 dev = rt->dev;
1641
1642 SOCK_DEBUG(sk, "SK %p: Size needed %d, device %s\n",
1643 sk, size, dev->name);
1644
1645 hard_header_len = dev->hard_header_len;
1646 /* Leave room for loopback hardware header if necessary */
1647 if (usat->sat_addr.s_node == ATADDR_BCAST &&
1648 (dev->flags & IFF_LOOPBACK || !(rt->flags & RTF_GATEWAY))) {
1649 struct atalk_addr at_lo;
1650
1651 at_lo.s_node = 0;
1652 at_lo.s_net = 0;
1653
1654 rt_lo = atrtr_find(&at_lo);
1655
1656 if (rt_lo && rt_lo->dev->hard_header_len > hard_header_len)
1657 hard_header_len = rt_lo->dev->hard_header_len;
1658 }
1659
1660 size += hard_header_len;
1661 release_sock(sk);
1662 skb = sock_alloc_send_skb(sk, size, (flags & MSG_DONTWAIT), &err);
1663 lock_sock(sk);
1664 if (!skb)
1665 goto out;
1666
1667 skb_reserve(skb, ddp_dl->header_length);
1668 skb_reserve(skb, hard_header_len);
1669 skb->dev = dev;
1670
1671 SOCK_DEBUG(sk, "SK %p: Begin build.\n", sk);
1672
1673 ddp = skb_put(skb, sizeof(struct ddpehdr));
1674 ddp->deh_len_hops = htons(len + sizeof(*ddp));
1675 ddp->deh_dnet = usat->sat_addr.s_net;
1676 ddp->deh_snet = at->src_net;
1677 ddp->deh_dnode = usat->sat_addr.s_node;
1678 ddp->deh_snode = at->src_node;
1679 ddp->deh_dport = usat->sat_port;
1680 ddp->deh_sport = at->src_port;
1681
1682 SOCK_DEBUG(sk, "SK %p: Copy user data (%zd bytes).\n", sk, len);
1683
1684 err = memcpy_from_msg(skb_put(skb, len), msg, len);
1685 if (err) {
1686 kfree_skb(skb);
1687 err = -EFAULT;
1688 goto out;
1689 }
1690
1691 if (sk->sk_no_check_tx)
1692 ddp->deh_sum = 0;
1693 else
1694 ddp->deh_sum = atalk_checksum(skb, len + sizeof(*ddp));
1695
1696 /*
1697 * Loopback broadcast packets to non gateway targets (ie routes
1698 * to group we are in)
1699 */
1700 if (ddp->deh_dnode == ATADDR_BCAST &&
1701 !(rt->flags & RTF_GATEWAY) && !(dev->flags & IFF_LOOPBACK)) {
1702 struct sk_buff *skb2 = skb_copy(skb, GFP_KERNEL);
1703
1704 if (skb2) {
1705 loopback = 1;
1706 SOCK_DEBUG(sk, "SK %p: send out(copy).\n", sk);
1707 /*
1708 * If it fails it is queued/sent above in the aarp queue
1709 */
1710 aarp_send_ddp(dev, skb2, &usat->sat_addr, NULL);
1711 }
1712 }
1713
1714 if (dev->flags & IFF_LOOPBACK || loopback) {
1715 SOCK_DEBUG(sk, "SK %p: Loop back.\n", sk);
1716 /* loop back */
1717 skb_orphan(skb);
1718 if (ddp->deh_dnode == ATADDR_BCAST) {
1719 if (!rt_lo) {
1720 kfree_skb(skb);
1721 err = -ENETUNREACH;
1722 goto out;
1723 }
1724 dev = rt_lo->dev;
1725 skb->dev = dev;
1726 }
1727 ddp_dl->request(ddp_dl, skb, dev->dev_addr);
1728 } else {
1729 SOCK_DEBUG(sk, "SK %p: send out.\n", sk);
1730 if (rt->flags & RTF_GATEWAY) {
1731 gsat.sat_addr = rt->gateway;
1732 usat = &gsat;
1733 }
1734
1735 /*
1736 * If it fails it is queued/sent above in the aarp queue
1737 */
1738 aarp_send_ddp(dev, skb, &usat->sat_addr, NULL);
1739 }
1740 SOCK_DEBUG(sk, "SK %p: Done write (%zd).\n", sk, len);
1741
1742 out:
1743 release_sock(sk);
1744 return err ? : len;
1745 }
1746
atalk_recvmsg(struct socket * sock,struct msghdr * msg,size_t size,int flags)1747 static int atalk_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1748 int flags)
1749 {
1750 struct sock *sk = sock->sk;
1751 struct ddpehdr *ddp;
1752 int copied = 0;
1753 int offset = 0;
1754 int err = 0;
1755 struct sk_buff *skb;
1756
1757 skb = skb_recv_datagram(sk, flags, &err);
1758 lock_sock(sk);
1759
1760 if (!skb)
1761 goto out;
1762
1763 /* FIXME: use skb->cb to be able to use shared skbs */
1764 ddp = ddp_hdr(skb);
1765 copied = ntohs(ddp->deh_len_hops) & 1023;
1766
1767 if (sk->sk_type != SOCK_RAW) {
1768 offset = sizeof(*ddp);
1769 copied -= offset;
1770 }
1771
1772 if (copied > size) {
1773 copied = size;
1774 msg->msg_flags |= MSG_TRUNC;
1775 }
1776 err = skb_copy_datagram_msg(skb, offset, msg, copied);
1777
1778 if (!err && msg->msg_name) {
1779 DECLARE_SOCKADDR(struct sockaddr_at *, sat, msg->msg_name);
1780 sat->sat_family = AF_APPLETALK;
1781 sat->sat_port = ddp->deh_sport;
1782 sat->sat_addr.s_node = ddp->deh_snode;
1783 sat->sat_addr.s_net = ddp->deh_snet;
1784 msg->msg_namelen = sizeof(*sat);
1785 }
1786
1787 skb_free_datagram(sk, skb); /* Free the datagram. */
1788
1789 out:
1790 release_sock(sk);
1791 return err ? : copied;
1792 }
1793
1794
1795 /*
1796 * AppleTalk ioctl calls.
1797 */
atalk_ioctl(struct socket * sock,unsigned int cmd,unsigned long arg)1798 static int atalk_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1799 {
1800 int rc = -ENOIOCTLCMD;
1801 struct sock *sk = sock->sk;
1802 void __user *argp = (void __user *)arg;
1803
1804 switch (cmd) {
1805 /* Protocol layer */
1806 case TIOCOUTQ: {
1807 long amount = sk->sk_sndbuf - sk_wmem_alloc_get(sk);
1808
1809 if (amount < 0)
1810 amount = 0;
1811 rc = put_user(amount, (int __user *)argp);
1812 break;
1813 }
1814 case TIOCINQ: {
1815 struct sk_buff *skb;
1816 long amount = 0;
1817
1818 spin_lock_irq(&sk->sk_receive_queue.lock);
1819 skb = skb_peek(&sk->sk_receive_queue);
1820 if (skb)
1821 amount = skb->len - sizeof(struct ddpehdr);
1822 spin_unlock_irq(&sk->sk_receive_queue.lock);
1823 rc = put_user(amount, (int __user *)argp);
1824 break;
1825 }
1826 /* Routing */
1827 case SIOCADDRT:
1828 case SIOCDELRT:
1829 rc = -EPERM;
1830 if (capable(CAP_NET_ADMIN))
1831 rc = atrtr_ioctl(cmd, argp);
1832 break;
1833 /* Interface */
1834 case SIOCGIFADDR:
1835 case SIOCSIFADDR:
1836 case SIOCGIFBRDADDR:
1837 case SIOCATALKDIFADDR:
1838 case SIOCDIFADDR:
1839 case SIOCSARP: /* proxy AARP */
1840 case SIOCDARP: /* proxy AARP */
1841 rtnl_lock();
1842 rc = atif_ioctl(cmd, argp);
1843 rtnl_unlock();
1844 break;
1845 }
1846
1847 return rc;
1848 }
1849
1850
1851 #ifdef CONFIG_COMPAT
atalk_compat_routing_ioctl(struct sock * sk,unsigned int cmd,struct compat_rtentry __user * ur)1852 static int atalk_compat_routing_ioctl(struct sock *sk, unsigned int cmd,
1853 struct compat_rtentry __user *ur)
1854 {
1855 compat_uptr_t rtdev;
1856 struct rtentry rt;
1857
1858 if (copy_from_user(&rt.rt_dst, &ur->rt_dst,
1859 3 * sizeof(struct sockaddr)) ||
1860 get_user(rt.rt_flags, &ur->rt_flags) ||
1861 get_user(rt.rt_metric, &ur->rt_metric) ||
1862 get_user(rt.rt_mtu, &ur->rt_mtu) ||
1863 get_user(rt.rt_window, &ur->rt_window) ||
1864 get_user(rt.rt_irtt, &ur->rt_irtt) ||
1865 get_user(rtdev, &ur->rt_dev))
1866 return -EFAULT;
1867
1868 switch (cmd) {
1869 case SIOCDELRT:
1870 if (rt.rt_dst.sa_family != AF_APPLETALK)
1871 return -EINVAL;
1872 return atrtr_delete(&((struct sockaddr_at *)
1873 &rt.rt_dst)->sat_addr);
1874
1875 case SIOCADDRT:
1876 rt.rt_dev = compat_ptr(rtdev);
1877 return atrtr_ioctl_addrt(&rt);
1878 default:
1879 return -EINVAL;
1880 }
1881 }
atalk_compat_ioctl(struct socket * sock,unsigned int cmd,unsigned long arg)1882 static int atalk_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1883 {
1884 void __user *argp = compat_ptr(arg);
1885 struct sock *sk = sock->sk;
1886
1887 switch (cmd) {
1888 case SIOCADDRT:
1889 case SIOCDELRT:
1890 return atalk_compat_routing_ioctl(sk, cmd, argp);
1891 /*
1892 * SIOCATALKDIFADDR is a SIOCPROTOPRIVATE ioctl number, so we
1893 * cannot handle it in common code. The data we access if ifreq
1894 * here is compatible, so we can simply call the native
1895 * handler.
1896 */
1897 case SIOCATALKDIFADDR:
1898 return atalk_ioctl(sock, cmd, (unsigned long)argp);
1899 default:
1900 return -ENOIOCTLCMD;
1901 }
1902 }
1903 #endif /* CONFIG_COMPAT */
1904
1905
1906 static const struct net_proto_family atalk_family_ops = {
1907 .family = PF_APPLETALK,
1908 .create = atalk_create,
1909 .owner = THIS_MODULE,
1910 };
1911
1912 static const struct proto_ops atalk_dgram_ops = {
1913 .family = PF_APPLETALK,
1914 .owner = THIS_MODULE,
1915 .release = atalk_release,
1916 .bind = atalk_bind,
1917 .connect = atalk_connect,
1918 .socketpair = sock_no_socketpair,
1919 .accept = sock_no_accept,
1920 .getname = atalk_getname,
1921 .poll = datagram_poll,
1922 .ioctl = atalk_ioctl,
1923 .gettstamp = sock_gettstamp,
1924 #ifdef CONFIG_COMPAT
1925 .compat_ioctl = atalk_compat_ioctl,
1926 #endif
1927 .listen = sock_no_listen,
1928 .shutdown = sock_no_shutdown,
1929 .sendmsg = atalk_sendmsg,
1930 .recvmsg = atalk_recvmsg,
1931 .mmap = sock_no_mmap,
1932 };
1933
1934 static struct notifier_block ddp_notifier = {
1935 .notifier_call = ddp_device_event,
1936 };
1937
1938 static struct packet_type ltalk_packet_type __read_mostly = {
1939 .type = cpu_to_be16(ETH_P_LOCALTALK),
1940 .func = ltalk_rcv,
1941 };
1942
1943 static struct packet_type ppptalk_packet_type __read_mostly = {
1944 .type = cpu_to_be16(ETH_P_PPPTALK),
1945 .func = atalk_rcv,
1946 };
1947
1948 static unsigned char ddp_snap_id[] = { 0x08, 0x00, 0x07, 0x80, 0x9B };
1949
1950 /* Export symbols for use by drivers when AppleTalk is a module */
1951 EXPORT_SYMBOL(atrtr_get_dev);
1952 EXPORT_SYMBOL(atalk_find_dev_addr);
1953
1954 /* Called by proto.c on kernel start up */
atalk_init(void)1955 static int __init atalk_init(void)
1956 {
1957 int rc;
1958
1959 rc = proto_register(&ddp_proto, 0);
1960 if (rc)
1961 goto out;
1962
1963 rc = sock_register(&atalk_family_ops);
1964 if (rc)
1965 goto out_proto;
1966
1967 ddp_dl = register_snap_client(ddp_snap_id, atalk_rcv);
1968 if (!ddp_dl) {
1969 pr_crit("Unable to register DDP with SNAP.\n");
1970 rc = -ENOMEM;
1971 goto out_sock;
1972 }
1973
1974 dev_add_pack(<alk_packet_type);
1975 dev_add_pack(&ppptalk_packet_type);
1976
1977 rc = register_netdevice_notifier(&ddp_notifier);
1978 if (rc)
1979 goto out_snap;
1980
1981 rc = aarp_proto_init();
1982 if (rc)
1983 goto out_dev;
1984
1985 rc = atalk_proc_init();
1986 if (rc)
1987 goto out_aarp;
1988
1989 rc = atalk_register_sysctl();
1990 if (rc)
1991 goto out_proc;
1992 out:
1993 return rc;
1994 out_proc:
1995 atalk_proc_exit();
1996 out_aarp:
1997 aarp_cleanup_module();
1998 out_dev:
1999 unregister_netdevice_notifier(&ddp_notifier);
2000 out_snap:
2001 dev_remove_pack(&ppptalk_packet_type);
2002 dev_remove_pack(<alk_packet_type);
2003 unregister_snap_client(ddp_dl);
2004 out_sock:
2005 sock_unregister(PF_APPLETALK);
2006 out_proto:
2007 proto_unregister(&ddp_proto);
2008 goto out;
2009 }
2010 module_init(atalk_init);
2011
2012 /*
2013 * No explicit module reference count manipulation is needed in the
2014 * protocol. Socket layer sets module reference count for us
2015 * and interfaces reference counting is done
2016 * by the network device layer.
2017 *
2018 * Ergo, before the AppleTalk module can be removed, all AppleTalk
2019 * sockets should be closed from user space.
2020 */
atalk_exit(void)2021 static void __exit atalk_exit(void)
2022 {
2023 #ifdef CONFIG_SYSCTL
2024 atalk_unregister_sysctl();
2025 #endif /* CONFIG_SYSCTL */
2026 atalk_proc_exit();
2027 aarp_cleanup_module(); /* General aarp clean-up. */
2028 unregister_netdevice_notifier(&ddp_notifier);
2029 dev_remove_pack(<alk_packet_type);
2030 dev_remove_pack(&ppptalk_packet_type);
2031 unregister_snap_client(ddp_dl);
2032 sock_unregister(PF_APPLETALK);
2033 proto_unregister(&ddp_proto);
2034 }
2035 module_exit(atalk_exit);
2036
2037 MODULE_LICENSE("GPL");
2038 MODULE_AUTHOR("Alan Cox <alan@lxorguk.ukuu.org.uk>");
2039 MODULE_DESCRIPTION("AppleTalk 0.20\n");
2040 MODULE_ALIAS_NETPROTO(PF_APPLETALK);
2041